An apple day keeps the doctor away but an unhealthy body makes you more susceptible to dementia, at least that’s what a new study in Japan is showing. The study links diabetes to an increased risk of contracting Alzheimer’s disease and other forms of dementia.

The research recently published in the journal Neurology included over 1,000 adults aged 60 and older who already had pre-existing memory issues, 15 percent who had diabetes and 23 percent who had pre-diabetes.

Results revealed that 232 people developed Alzheimer’s and those with diabetes were twice as likely to develop the disease. Pre-diabetics were also more prone to Alzheimer’s.

Dr. Rachel Whitmer, an epidemiologist told CNN: "It's really important for the [public's] health to understand that diabetes is a significant risk factor for all of these types of dementia.”

Yutaka Kiyohara, M.D., an environmental medicine researcher at Kyushu University, in Fukuoka leading author of the study wanted to expose the weakness by conducting oral glucose tolerance tests. Each person was given a sugary drink after not eating for 12 hours and the glucose level was measured two hours later. At the end of the study all participants were dementia free but over 15 years 23 percent were diagnosed with dementia.

David Geldmacher, M.D and professor of neurology at the University of Alabama at Birmingham told CNN, "Having high glucose is a stressor to the nervous system and to the blood vessels. The emerging information on Alzheimer's disease and glucose shows us that we do need to remain vigilant on blood sugar levels as we get older.”

Follow us

The exact cause for this increased risk has not been confirmed but there are a few theories. According to Health.com, insulin resistance, which leads to type 2diabetes, may reduce the body’s ability to break down the protein that forms brain plaques that have been connected to Alzheimer’s.

High sugar levels and high cholesterol can cause the narrowing of arteries, a condition called atherosclerosis, which kills brain cells, also could contribute to developing the neurological disease.

Whitmer said that the study provided “really good evidence that people with diabetes are at greater risk.”

“But we really need to look at other studies to find out why."

The results of the study are still undergoing investigation in order to help reduce dementia risks.